Abstract
In the study of car following, it is important to examine the behavioral process of the driver while following a car. In modeling the behavior of a driver it is necessary to quantify certain parameters which describe the driver' s perceptual processes. The parameter of interest is headway change determination. Two problems of headway change detection are absolute motion threshold. By means of a series of experiments this study presents some of the principles in understanding the variables that affect driver' s ability to detect movement in the form of headway changes.